2 # For a description of the syntax of this configuration file,
3 # see docs/Kconfig-language.txt.
6 mainmenu "Configuration"
15 bool "Enable compatibility for full-blown desktop systems (8kb)"
18 Enable applet options and features which are not essential.
19 Many applet options have dedicated config options to (de)select them
20 under that applet; this options enables those options which have no
21 individual config item for them.
23 Select this if you plan to use busybox on full-blown desktop machine
24 with common Linux distro, which needs higher level of command-line
27 If you are preparing your build to be used on an embedded box
28 where you have tighter control over the entire set of userspace
29 tools, you can unselect this option for smaller code size.
32 bool "Provide compatible behavior for rare corner cases (bigger code)"
35 This option makes grep, sed etc handle rare corner cases
36 (embedded NUL bytes and such). This makes code bigger and uses
37 some GNU extensions in libc. You probably only need this option
38 if you plan to run busybox on desktop.
41 bool "Building for Fedora distribution"
44 This option makes some tools behave like they do on Fedora.
46 At the time of this writing (2017-08) this only affects uname:
47 normally, uname -p (processor) and uname -i (platform)
48 are shown as "unknown", but with this option uname -p
49 shows the same string as uname -m (machine type),
50 and so does uname -i unless machine type is i486/i586/i686 -
51 then uname -i shows "i386".
54 bool "Enable obsolete features removed before SUSv3"
57 This option will enable backwards compatibility with SuSv2,
58 specifically, old-style numeric options ('command -1 <file>')
59 will be supported in head, tail, and fold. (Note: should
63 bool "Support --long-options"
66 Enable this if you want busybox applets to use the gnu --long-option
67 style, in addition to single character -a -b -c style options.
70 bool "Show applet usage messages"
73 Enabling this option, applets will show terse help messages
74 when invoked with wrong arguments.
75 If you do not want to show any (helpful) usage message when
76 issuing wrong command syntax, you can say 'N' here,
77 saving approximately 7k.
79 config FEATURE_VERBOSE_USAGE
80 bool "Show verbose applet usage messages"
84 All applets will show verbose help messages when invoked with --help.
85 This will add a lot of text to the binary.
87 config FEATURE_COMPRESS_USAGE
88 bool "Store applet usage messages in compressed form"
92 Store usage messages in .bz2 compressed form, uncompress them
93 on-the-fly when "APPLET --help" is run.
95 If you have a really tiny busybox with few applets enabled (and
96 bunzip2 isn't one of them), the overhead of the decompressor might
97 be noticeable. Also, if you run executables directly from ROM
98 and have very little memory, this might not be a win. Otherwise,
99 you probably want this.
102 bool "Support files > 2 GB"
105 If you need to work with large files, enable this option.
106 This will have no effect if your kernel or your C
107 library lacks large file support for large files. Some of the
108 programs that can benefit from large file support include dd, gzip,
112 bool "Support 64bit wide time types"
116 Make times later than 2038 representable for several libc syscalls
117 (stat, clk_gettime etc.). Note this switch is specific to glibc
118 and has no effect on platforms that already use 64bit wide time types
119 (i.e. all 64bit archs and some selected 32bit archs (currently riscv
123 bool "Support PAM (Pluggable Authentication Modules)"
126 Use PAM in some applets (currently login and httpd) instead
127 of direct access to password database.
129 config FEATURE_DEVPTS
130 bool "Use the devpts filesystem for Unix98 PTYs"
133 Enable if you want to use Unix98 PTY support. If enabled,
134 busybox will use /dev/ptmx for the master side of the pseudoterminal
135 and /dev/pts/<number> for the slave side. Otherwise, BSD style
136 /dev/ttyp<number> will be used. To use this option, you should have
140 bool "Support utmp file"
143 The file /var/run/utmp is used to track who is currently logged in.
144 With this option on, certain applets (getty, login, telnetd etc)
145 will create and delete entries there.
146 "who" applet requires this option.
149 bool "Support wtmp file"
151 depends on FEATURE_UTMP
153 The file /var/run/wtmp is used to track when users have logged into
154 and logged out of the system.
155 With this option on, certain applets (getty, login, telnetd etc)
156 will append new entries there.
157 "last" applet requires this option.
159 config FEATURE_PIDFILE
160 bool "Support writing pidfiles"
163 This option makes some applets (e.g. crond, syslogd, inetd) write
164 a pidfile at the configured PID_FILE_PATH. It has no effect
165 on applets which require pidfiles to run.
168 string "Directory for pidfiles"
170 depends on FEATURE_PIDFILE || FEATURE_CROND_SPECIAL_TIMES
172 This is the default path where pidfiles are created. Applets which
173 allow you to set the pidfile path on the command line will override
174 this value. The option has no effect on applets that require you to
175 specify a pidfile path. When crond has the 'Support special times'
176 option enabled, the 'crond.reboot' file is also stored here.
179 bool "Include busybox applet"
182 The busybox applet provides general help message and allows
183 the included applets to be listed. It also provides
184 optional --install command to create applet links. If you unselect
185 this option, running busybox without any arguments will give
186 just a cryptic error message:
189 busybox: applet not found
191 Running "busybox APPLET [ARGS...]" will still work, of course.
193 config FEATURE_SHOW_SCRIPT
194 bool "Support --show SCRIPT"
198 config FEATURE_INSTALLER
199 bool "Support --install [-s] to install applet links at runtime"
203 Enable 'busybox --install [-s]' support. This will allow you to use
204 busybox at runtime to create hard links or symlinks for all the
205 applets that are compiled into busybox.
207 config INSTALL_NO_USR
208 bool "Don't use /usr"
211 Disable use of /usr. "busybox --install" and "make install"
212 will install applets only to /bin and /sbin,
213 never to /usr/bin or /usr/sbin.
216 bool "Drop SUID state for most applets"
219 With this option you can install the busybox binary belonging
220 to root with the suid bit set, enabling some applets to perform
221 root-level operations even when run by ordinary users
222 (for example, mounting of user mounts in fstab needs this).
224 With this option enabled, busybox drops privileges for applets
225 that don't need root access, before entering their main() function.
227 If you are really paranoid and don't want even initial busybox code
228 to run under root for every applet, build two busybox binaries with
229 different applets in them (and the appropriate symlinks pointing
230 to each binary), and only set the suid bit on the one that needs it.
232 Some applets which require root rights (need suid bit on the binary
233 or to be run by root) and will refuse to execute otherwise:
234 crontab, login, passwd, su, vlock, wall.
236 The applets which will use root rights if they have them
237 (via suid bit, or because run by root), but would try to work
238 without root right nevertheless:
239 findfs, ping[6], traceroute[6], mount.
241 Note that if you DO NOT select this option, but DO make busybox
242 suid root, ALL applets will run under root, which is a huge
243 security hole (think "cp /some/file /etc/passwd").
245 config FEATURE_SUID_CONFIG
246 bool "Enable SUID configuration via /etc/busybox.conf"
248 depends on FEATURE_SUID
250 Allow the SUID/SGID state of an applet to be determined at runtime
251 by checking /etc/busybox.conf. (This is sort of a poor man's sudo.)
252 The format of this file is as follows:
254 APPLET = [Ssx-][Ssx-][x-] [USER.GROUP]
256 s: USER or GROUP is allowed to execute APPLET.
257 APPLET will run under USER or GROUP
258 (regardless of who's running it).
259 S: USER or GROUP is NOT allowed to execute APPLET.
260 APPLET will run under USER or GROUP.
261 This option is not very sensical.
262 x: USER/GROUP/others are allowed to execute APPLET.
263 No UID/GID change will be done when it is run.
264 -: USER/GROUP/others are not allowed to execute APPLET.
266 An example might help:
269 |su = ssx root.0 # applet su can be run by anyone and runs with
271 |su = ssx # exactly the same
273 |mount = sx- root.disk # applet mount can be run by root and members
274 | # of group disk (but not anyone else)
275 | # and runs with euid=0 (egid is not changed)
277 |cp = --- # disable applet cp for everyone
279 The file has to be owned by user root, group root and has to be
280 writeable only by root:
281 (chown 0.0 /etc/busybox.conf; chmod 600 /etc/busybox.conf)
282 The busybox executable has to be owned by user root, group
283 root and has to be setuid root for this to work:
284 (chown 0.0 /bin/busybox; chmod 4755 /bin/busybox)
286 Robert 'sandman' Griebl has more information here:
287 <url: http://www.softforge.de/bb/suid.html >.
289 config FEATURE_SUID_CONFIG_QUIET
290 bool "Suppress warning message if /etc/busybox.conf is not readable"
292 depends on FEATURE_SUID_CONFIG
294 /etc/busybox.conf should be readable by the user needing the SUID,
295 check this option to avoid users to be notified about missing
298 config FEATURE_PREFER_APPLETS
299 bool "exec prefers applets"
302 This is an experimental option which directs applets about to
303 call 'exec' to try and find an applicable busybox applet before
304 searching the PATH. This is typically done by exec'ing
307 This may affect shell, find -exec, xargs and similar applets.
308 They will use applets even if /bin/APPLET -> busybox link
309 is missing (or is not a link to busybox). However, this causes
310 problems in chroot jails without mounted /proc and with ps/top
311 (command name can be shown as 'exe' for applets started this way).
313 config BUSYBOX_EXEC_PATH
314 string "Path to busybox executable"
315 default "/proc/self/exe"
317 When applets need to run other applets, busybox
318 sometimes needs to exec() itself. When the /proc filesystem is
319 mounted, /proc/self/exe always points to the currently running
320 executable. If you haven't got /proc, set this to wherever you
321 want to run busybox from.
324 bool "Support NSA Security Enhanced Linux"
327 Enable support for SELinux in applets ls, ps, and id. Also provide
328 the option of compiling in SELinux applets.
330 If you do not have a complete SELinux userland installed, this stuff
331 will not compile. Specifially, libselinux 1.28 or better is
332 directly required by busybox. If the installation is located in a
333 non-standard directory, provide it by invoking make as follows:
335 CFLAGS=-I<libselinux-include-path> \
336 LDFLAGS=-L<libselinux-lib-path> \
339 Most people will leave this set to 'N'.
341 config FEATURE_CLEAN_UP
342 bool "Clean up all memory before exiting (usually not needed)"
345 As a size optimization, busybox normally exits without explicitly
346 freeing dynamically allocated memory or closing files. This saves
347 space since the OS will clean up for us, but it can confuse debuggers
348 like valgrind, which report tons of memory and resource leaks.
350 Don't enable this unless you have a really good reason to clean
353 config FEATURE_SYSLOG_INFO
354 bool "Support LOG_INFO level syslog messages"
356 depends on FEATURE_SYSLOG
358 Applets which send their output to syslog use either LOG_INFO or
359 LOG_ERR log levels, but by disabling this option all messages will
360 be logged at the LOG_ERR level, saving just under 200 bytes.
362 # These are auto-selected by other options
364 config FEATURE_SYSLOG
365 bool #No description makes it a hidden option
368 #This option is auto-selected when you select any applet which may
369 #send its output to syslog. You do not need to select it manually.
371 comment 'Build Options'
374 bool "Build static binary (no shared libs)"
377 If you want to build a static binary, which does not use
378 or require any shared libraries, enable this option.
379 Static binaries are larger, but do not require functioning
380 dynamic libraries to be present, which is important if used
381 as a system rescue tool.
384 bool "Build position independent executable"
388 Hardened code option. PIE binaries are loaded at a different
389 address at each invocation. This has some overhead,
390 particularly on x86-32 which is short on registers.
392 Most people will leave this set to 'N'.
395 bool "Force NOMMU build"
398 Busybox tries to detect whether architecture it is being
399 built against supports MMU or not. If this detection fails,
400 or if you want to build NOMMU version of busybox for testing,
401 you may force NOMMU build here.
403 Most people will leave this set to 'N'.
405 # PIE can be made to work with BUILD_LIBBUSYBOX, but currently
406 # build system does not support that
407 config BUILD_LIBBUSYBOX
408 bool "Build shared libbusybox"
410 depends on !FEATURE_PREFER_APPLETS && !PIE && !STATIC
412 Build a shared library libbusybox.so.N.N.N which contains all
415 This feature allows every applet to be built as a really tiny
416 separate executable linked against the library:
418 | text data bss dec hex filename
419 | 939 212 28 1179 49b 0_lib/last
420 | 939 212 28 1179 49b 0_lib/less
421 | 919138 8328 1556 929022 e2cfe 0_lib/libbusybox.so.1.N.M
423 This is useful on NOMMU systems which are not capable
424 of sharing executables, but are capable of sharing code
425 in dynamic libraries.
427 config FEATURE_LIBBUSYBOX_STATIC
428 bool "Pull in all external references into libbusybox"
430 depends on BUILD_LIBBUSYBOX
432 Make libbusybox library independent, not using or requiring
433 any other shared libraries.
435 config FEATURE_INDIVIDUAL
436 bool "Produce a binary for each applet, linked against libbusybox"
438 depends on BUILD_LIBBUSYBOX
440 If your CPU architecture doesn't allow for sharing text/rodata
441 sections of running binaries, but allows for runtime dynamic
442 libraries, this option will allow you to reduce memory footprint
443 when you have many different applets running at once.
445 If your CPU architecture allows for sharing text/rodata,
446 having single binary is more optimal.
448 Each applet will be a tiny program, dynamically linked
449 against libbusybox.so.N.N.N.
451 You need to have a working dynamic linker.
453 config FEATURE_SHARED_BUSYBOX
454 bool "Produce additional busybox binary linked against libbusybox"
456 depends on BUILD_LIBBUSYBOX
458 Build busybox, dynamically linked against libbusybox.so.N.N.N.
460 You need to have a working dynamic linker.
462 ### config BUILD_AT_ONCE
463 ### bool "Compile all sources at once"
466 ### Normally each source-file is compiled with one invocation of
468 ### If you set this option, all sources are compiled at once.
469 ### This gives the compiler more opportunities to optimize which can
470 ### result in smaller and/or faster binaries.
472 ### Setting this option will consume alot of memory, e.g. if you
473 ### enable all applets with all features, gcc uses more than 300MB
474 ### RAM during compilation of busybox.
476 ### This option is most likely only beneficial for newer compilers
477 ### such as gcc-4.1 and above.
479 ### Say 'N' unless you know what you are doing.
481 config CROSS_COMPILER_PREFIX
482 string "Cross compiler prefix"
485 If you want to build busybox with a cross compiler, then you
486 will need to set this to the cross-compiler prefix, for example,
489 Note that CROSS_COMPILE environment variable or
490 "make CROSS_COMPILE=xxx ..." will override this selection.
492 Native builds leave this empty.
495 string "Path to sysroot"
498 If you want to build busybox with a cross compiler, then you
499 might also need to specify where /usr/include and /usr/lib
502 For example, busybox can be built against an installed
503 Android NDK, platform version 9, for ARM ABI with
505 CONFIG_SYSROOT=/opt/android-ndk/platforms/android-9/arch-arm
507 Native builds leave this empty.
510 string "Additional CFLAGS"
513 Additional CFLAGS to pass to the compiler verbatim.
516 string "Additional LDFLAGS"
519 Additional LDFLAGS to pass to the linker verbatim.
522 string "Additional LDLIBS"
525 Additional LDLIBS to pass to the linker with -l.
527 config USE_PORTABLE_CODE
528 bool "Avoid using GCC-specific code constructs"
531 Use this option if you are trying to compile busybox with
532 compiler other than gcc.
533 If you do use gcc, this option may needlessly increase code size.
535 config STACK_OPTIMIZATION_386
536 bool "Use -mpreferred-stack-boundary=2 on i386 arch"
539 This option makes for smaller code, but some libc versions
540 do not work with it (they use SSE instructions without
541 ensuring stack alignment).
544 bool "Use -static-libgcc"
547 This option instructs gcc to link in a static version of its
548 support library, libgcc. This means that the binary will require
549 one fewer dynamic library at run time.
551 comment 'Installation Options ("make install" behavior)'
554 prompt "What kind of applet links to install"
555 default INSTALL_APPLET_SYMLINKS
557 Choose what kind of links to applets are created by "make install".
559 config INSTALL_APPLET_SYMLINKS
562 Install applets as soft-links to the busybox binary. This needs some
563 free inodes on the filesystem, but might help with filesystem
564 generators that can't cope with hard-links.
566 config INSTALL_APPLET_HARDLINKS
569 Install applets as hard-links to the busybox binary. This might
570 count on a filesystem with few inodes.
572 config INSTALL_APPLET_SCRIPT_WRAPPERS
573 bool "as script wrappers"
575 Install applets as script wrappers that call the busybox binary.
577 config INSTALL_APPLET_DONT
580 Do not install applet links. Useful when you plan to use
581 busybox --install for installing links, or plan to use
582 a standalone shell and thus don't need applet links.
587 prompt "/bin/sh applet link"
588 default INSTALL_SH_APPLET_SYMLINK
589 depends on INSTALL_APPLET_SCRIPT_WRAPPERS
591 Choose how you install /bin/sh applet link.
593 config INSTALL_SH_APPLET_SYMLINK
596 Install /bin/sh applet as soft-link to the busybox binary.
598 config INSTALL_SH_APPLET_HARDLINK
601 Install /bin/sh applet as hard-link to the busybox binary.
603 config INSTALL_SH_APPLET_SCRIPT_WRAPPER
604 bool "as script wrapper"
606 Install /bin/sh applet as script wrapper that calls
612 string "Destination path for 'make install'"
615 Where "make install" should install busybox binary and links.
617 comment 'Debugging Options'
620 bool "Build with debug information"
623 Say Y here to compile with debug information.
624 This increases the size of the binary considerably, and
625 should only be used when doing development.
627 This adds -g option to gcc command line.
629 Most people should answer N.
631 config DEBUG_PESSIMIZE
632 bool "Disable compiler optimizations"
636 The compiler's optimization of source code can eliminate and reorder
637 code, resulting in an executable that's hard to understand when
638 stepping through it with a debugger. This switches it off, resulting
639 in a much bigger executable that more closely matches the source
642 This replaces -Os/-O2 with -O0 in gcc command line.
644 config DEBUG_SANITIZE
645 bool "Enable runtime sanitizers (ASAN/LSAN/USAN/etc...)"
648 Say Y here if you want to enable runtime sanitizers. These help
649 catch bad memory accesses (e.g. buffer overflows), but will make
650 the executable larger and slow down runtime a bit.
652 This adds -fsanitize=foo options to gcc command line.
654 If you aren't developing/testing busybox, say N here.
657 bool "Build unit tests"
660 Say Y here if you want to build unit tests (both the framework and
661 test cases) as an applet. This results in bigger code, so you
662 probably don't want this option in production builds.
665 bool "Abort compilation on any warning"
668 This adds -Werror to gcc command line.
670 Most people should answer N.
672 config WARN_SIMPLE_MSG
673 bool "Warn about single parameter bb_xx_msg calls"
676 This will cause warnings to be shown for any instances of
677 bb_error_msg(), bb_error_msg_and_die(), bb_perror_msg(),
678 bb_perror_msg_and_die(), bb_herror_msg() or bb_herror_msg_and_die()
679 being called with a single parameter. In these cases the equivalent
680 bb_simple_xx_msg function should be used instead.
681 Note that use of STRERROR_FMT may give false positives.
683 If you aren't developing busybox, say N here.
686 prompt "Additional debugging library"
689 Using an additional debugging library will make busybox become
690 considerably larger and will cause it to run more slowly. You
691 should always leave this option disabled for production use.
695 This enables compiling with dmalloc ( http://dmalloc.com/ )
696 which is an excellent public domain mem leak and malloc problem
697 detector. To enable dmalloc, before running busybox you will
698 want to properly set your environment, for example:
699 export DMALLOC_OPTIONS=debug=0x34f47d83,inter=100,log=logfile
700 The 'debug=' value is generated using the following command
701 dmalloc -p log-stats -p log-non-free -p log-bad-space \
702 -p log-elapsed-time -p check-fence -p check-heap \
703 -p check-lists -p check-blank -p check-funcs -p realloc-copy \
706 Electric-fence support:
707 -----------------------
708 This enables compiling with Electric-fence support. Electric
709 fence is another very useful malloc debugging library which uses
710 your computer's virtual memory hardware to detect illegal memory
711 accesses. This support will make busybox be considerably larger
712 and run slower, so you should leave this option disabled unless
713 you are hunting a hard to find memory problem.
723 bool "Electric-fence"
727 source libbb/Config.in
733 source archival/Config.in
734 source coreutils/Config.in
735 source console-tools/Config.in
736 source debianutils/Config.in
737 source klibc-utils/Config.in
738 source editors/Config.in
739 source findutils/Config.in
740 source init/Config.in
741 source loginutils/Config.in
742 source e2fsprogs/Config.in
743 source modutils/Config.in
744 source util-linux/Config.in
745 source miscutils/Config.in
746 source networking/Config.in
747 source printutils/Config.in
748 source mailutils/Config.in
749 source procps/Config.in
750 source runit/Config.in
751 source selinux/Config.in
752 source shell/Config.in
753 source sysklogd/Config.in